1. Field of the Invention
The present invention relates to a therapeutical method for treating children affected by learning disorders and, more specifically, to a method for treating children suffering from Attention-Deficit/Hyperactive Disorder (ADHD).
2. Description of the Prior Art
ADHD is a developmentally inappropriate inattention and impulsivity generally associated with hyperactivity.
ADHD diagnostic criteria are precisely set forth in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), pages 82-85, published by the American Psychiatric Association.
ADHD diagnosis should in fact be made with great care and only if the symptoms of inattention or hyperactivity are excessive for the child's mental age. Inattention in the classroom may also occur when children with high intelligence are placed in academically understimulating environments.
ADHD is a heterogenous disorder of unknown etiology. It is one of the major clinical and public health problems worldwide because of its associated morbidity and disability in children and adolescents.
Its impact on society is enormous in terms of the financial cost, the stress to families, the impact on academic and vocational activities. The symptoms of this syndrome are distressing to the environment (parents and teachers) and also distressful to the child. The disorder is usually accompanied by impairment of social and school functioning and in the majority of cases persists throughout childhood.
Moreover, prospective longitudinal studies of hyperkinetic children indicate that a substantial proportion thereof retains hyperkinetic symptoms and goes on to antisocial disorders.
ADHD affects approximately 5 to 10% of school-aged children youths according to epidemiological studies carried out in the United States and Europe. ADHD is seen 10 times more frequently in boys than in girls.
ADHD is a common cause of referrals to pediatricians and child psychiatrists and accounts approximately for as 50% of child psychiatric clinic population.
The affected children do not necessarily share a common set of characteristics. However, most of the children show deficiencies in their attention span, impulse control, and rule-governed behaviour. The common hyperactivity and impulsivity symptoms are described as follows. The children often fidget with hands or feet, leave seat in the classroom or at home during meals, have difficulty awaiting turn, blurt out answers before questions have been completed, often talk excessively, interrupt or intrude on others, often run about in situations in which it is inappropriate.
On the other side the common inattention symptoms are described as follows. The children often fail to give attention to details or make careless mistakes in school work or other daily activities. They also have difficulty in sustaining attention in tasks or play activities, are easily distracted by extraneous stimuli, often do not seem to listen when spoken to directly, do not follow through on instructions and fail to finish school work or daily duties. Often they are unmotivated to do school or home work, avoid tasks that require sustained mental effort, often lose things necessary for tasks or activities and are forgetful in common daily activities. In some children the hyperactivity-impulsivity are predominant on the attention deficit disorder, whereas in other children the attention deficit is predominant. Mostly the hyperactivity-impulsivity and attention deficit symptoms are combined.
As previously indicated, ADHD etiology is unknown. Genetic factors, prenatal and perinatal acquired brain damage have been proposed as causes of the disease; yet no definitive conclusions has been reached. Recently, it has been suggested that the affected children are suffering from a disorder in energetical regulation mechanisms.
The psychopharmacological agents so far proposed to treat the disease are stimulant compounds (amphetamine and methylfenidate), tricyclics antidepressants (imipramine, amitryptiline) and antipsychotic agents (phenothiazines, haloperidol).
Two compounds are mostly used worldwide: methylfenidate and clonidine. The latter is primarily used as a central antihypertensive agent.
Methylfenidate has been object of several clinical studies that have proved a good efficacy both in hyperactivity and in attention deficit. However, rebound of hyperactivity has been often reported and sometimes impulsivity has been shown to increase.
Frequent adverse effects are reported during treatment with methylfenidate such as weary dark rings under the eyes, enlarged pupils, headache and decreased appetite.
Also difficulty in falling asleep, night awakening, bed wetting, drowsiness, reduction of systolic and diasystolic blood pressure have been reported. The most common side effects are insomnia, decreased appetite and weight loss.
Clonidine is also effective on home/school hyperactivity and on attention disorders but its beneficial effects on target problems with teachers and parents are less significant than those achieved with methylfenidate.
The adverse effects of clonidine are various and frequent. Drowsiness is the most common. An increased need for short naps has been also reported.
Frequent are also night awakening, sometimes accompanied by nightmares. Also nausea, decreased appetite and dry mouth have been reported. Reduction of systolic and diasystolic blood pressure occurs more frequently than with methylfenidate treatment.
The adverse effects of both compounds, i.e., methylfenidate and clonidine, have been recorded during the clinical trials and also reported by patients not participating to the trials as well as by parents and teachers.
It is, therefore, an object of the present invention to provide a therapeutical method for the treatment of children suffering from ADHD which comprises administering to children in need thereof a drug which is not only at least as effective as the known drugs, but which also does not present the aforesaid drawbacks and objectionable side effects of the known drugs.